Aircraft require a high level of maintenance and care to assure their safe use. Most aircraft comprise a metallic fuselage that is held together by metallic rivets. Both the fuselage and the rivets may occasionally require scanning to determine if weaknesses have developed within the metal.
Aircraft surface scanning may be accomplished using a sensor that detects changes in eddy currents as the sensor is passed over the surface of the aircraft. To avoid variations in the feedback from the sensor the sensor may be maintained at approximately the same distance from the surface of the aircraft as the sensor is passed over the surface of the aircraft. Difficulties arise in maintaining the sensor at approximately the same distance from the surface of the aircraft due to variations in the angle of the surface of the aircraft.